Electrical plug connectors



Sept. 27, 1960 J. w. FOCOSI ELECTRICAL PLUG CONNECTORS Filed July 22,1957 m 2 M M w 0 5 v w M 5 0 a R 4 6 2 6 M, 3 3 2 Wu %fiw F M/Vf/VTOI?!JOSE/ H l l/ FOCUS/ ATT'Y 2,954,544 ELECTRICAL PLUG CoNNEcToRs Joseph W.Focosi, 5119 N. Nagle Ave., Chicago 36, '11]. Filed July 22, 1957, Ser.No. 673,256 1 Claim. 01. 339- 182) This invention relates in general toan automotive accessory plug and is more particularly described as anelectrical plug connector adapted to make electrical connection with anelectric outlet socket now usually installed on automobile panel boardsfor use with cigarette lighting and electrical equipment, but which mayhave a more general application with any electric lighting socket.

The electric socket now commonly installed upon the front panel board ofan automobile and sometimes in other accessible places may now be usedfor connecting and illuminating automobile safety flares and signals,heating baby bottles, operating electric shavers and other similar usesas well as for the installed cigarette lighters.

In the present application, a quick acting accessory plug is providedwhich may be inserted or slipped readily in place which will tightlyengage the center and a side contact of the socket by simply sliding theplug into position, and at the same time providing an outer handle forinserting and removing the plug.

An important object of the invention is to provide an accessory plug inwhich both contacts are spring pressed so that the plug may be pushed orslipped into engagement with a sliding movement instead of a rotarymovement;

A further object of the invention is to provide an accessory plug havinga portion serving as a handle for inserting and removing the plug fromits connection with a. socket; to provide improved means for connectingthe contact elements of the plug with wire conductor terminals; toprovide improved means for attaching contact members at the ends ofconductor wires; to provide improved means for producing and attachingconductors to the ends of conductor wires; to provide improved terminalsfor self-locking engagement; and to provide a construction for reversingpolarity when desired.

Other objects of the invention will be apparent from the accompanyingdrawings, in which,

Fig. 1 is a perspective view of an accessory plug in accordance withthis invention;

Fig. 2 is an enlarged split view of an accessory plug casing as shown inFig. 1, showing the conductors within the plug and the conductor wireattachments thereto as the plug is applied in a socket;

Fig. 3 is a fragmentary view of an improved conductor fastening; Fig. 4is a perspective view of a modi fied conductor terminal; Fig. 5 is aperspective view of conductor terminal with a straight tip;

Fig. 6 is a perspective view of a portion of a strip of conductorcontacts; and Fig. 7 is a perspective view showing the contacts of Fig.6 as applied to the ends of conductor wires.

This accessory plug is made of complementary halves with conductorsassembled in one part and the two parts then riveted or otherwisetightly connected together with provisions for securely attachingcontact at the ends of the conductors inserted through openings at theend of latent O i Patented Sept. 27, 1960 the casing. The contacts areattached to the ends of the conductors before they are inserted in thecasing.

Referring now more particularly to the drawings, this plug connectorcomprises two similar casing parts 10 and 12 which when placed togetherhave a longitudinal split forming a circular contact portion at one endand a somewhat flattened handle portion at the other end and thelongitudinal split is on a substantially diametric central plane forassembling the parts in the casing. These casing parts 10 and '12 are ofhard plastic or other other suitable non-conductors and aresubstantially hollow at the inside except for certain connectingoperating parts. In one end of each casing part is a semi-circularrecess 14 for seating a circular contact tip 16 therein, the easing parthaving a cross partition 18 spaced a short distance within this end andalso having a recess 20 therein for seating the tip. At the inner end ofthe tip is a flange 22 which bears against the inner side of thepartition 18 and is held in resilient engagement therewith by a bentspring contact 24 firmly attached at one end to the inner end of thetip. The outer end of the tip 16 is rounded to make a good electricalengagement.

At one edge of the casing 10 is an inwardly recessed flat portion 26having slots 28 and 30 at the ends and inwardly extending projections 32and 34 at the ends of the flat portion 26. This provides an inwardlyopening recess 36 into which a sharp angular bend 38 of the springcontact 24 and is movable freely back and forth therein. The other endof this contact 24 has an angul'arly bent extremity 40 hooked around apost 42 formed in the handle end of the casing. The spring contact 24being made of metal, resiliently presses the flange 22 of the tip 16against the partition 18 and any depression of the tip causes theangular bend 38 to move freely backward in the recess 36.

Another bent spring metal contact 44 has an angularly offset portion 46which projects outwardly through the slot 30 on the outside of the flatportion 26 and inwardly through the slot 28 with one bent end 48disposed within the casing and engaging the inner side thereof adjacentthe cross partition 18. The other end of this spring contact 44 ishooked around a post 50 and has an angul'arly bent extremity 52extending inwardly from the post. The flat portion 26 and theprojections 32 and 34 provide means for spacing the metal contacts 24and 44 apart and also eliminate arcing of the current between them.

Between the posts 42 and 50 is a longitudinal partition 54 with aconnected cross piece 56 at the inner end, the partition 54 and theposts 42 and 50 being of a length to extend above the split line betweenthe casing parts and to extend into corresponding recesses (not shown)in the casing part 12. Also at the other end of the plug are twoprojections 58 which register with recesses (not shown) in the othercasing part 12, these projections and the partition serving to registerand position the casing parts in alignment. In order to secure thecasing parts with the spring contacts therein tightly together, a screwor rivet 60 is inserted through registering perforations in bosses 62located centrally of the casing parts and the ends of the rivets or theother fastening means are seated in the recesses 64 in the outer sidesof the casing parts.

In order to prevent the spring contacts 24 and 44 from moving away fromtheir respective posts 42 and 50, ribs 66 and 68 are provided near thehandle end of the plug connector which extend up close to the respectiveposts 42 and 50, but are separated from the posts by slots 70 and 72respectively into which the edges of the spring contacts 24 and 44 areseated, the angular bent extremities 40 and 52 hearing resiliently butagainst the intermediate partition 54 which separate them when there areI no conductors attached to the plug.

In order to connect a pair of conductors 74 and 76 of the twin connectedtype and preferably having stranded copper wires 78 in the plug, eachconductor has a terminal:80 (FigsLZ and, 7) i with portions 82 wrappedaroundv the extremity of the wire insulation ofthe conductor and teeth,84 formed up of the material between the wrapping portions 82. so thatwhen these portions are crimpedupon the insulated end of the conductor,they will penetrate the wrapping and willengage-the stranded wires78-:makinga: satisfactory electrical connection therewith. Theouter end.of each terminal 80 has a hat portion 86 withan angularly bent extremity88.

In'Fig. 4, a terminal 81 is shown having teeth 83 at the sides bendableover the insulation 74 of a conductor and havingsmaller teeth 85 at thesides bendable over stripped metal wires at'the end of the conductor. Aportion: 87 ,is curved'instead of fiat and an extremity 89 is bentangularly to-the adjacent curved portion 37. This cont-act makes a firmengagement with the bent extremities 49' and 52 of the spring contactswhen inserted in the endiof a plug.

Inapplying these terminals 80 (and 81) to a pair of connected conductorwires, the fiat portions 86 are at the insides andthe bent extremities88 extend outwardly so that when these conductors are to be connectedinto the'plug, the terminals 80 are inserted in the handle end of theplug at opposite sides of the partition 54 and are pushedinwardlyagainst the bent extremities 40 and 52 of the spring. contacts 24 and 44respectively as shown more clearly inFig. 2 so that these bentextremities extend over the ends of thebent extremities 4d and 52 andare pressed by them tightly against the partition 54 holding theterminals and conductors attached thereto tightly in placeand in goodelectrical contact.

The terminal 80 as shown in Fig. 5 is made up of a fiat extremity 86 andthe wrapping portion 82 which is applied to a conductor is shown withthe teeth 84 indented inwardly. The outer flat portion 86 may be formedwithout the outer bent extremity 38 and if inserted in a plug in suchcondition, the terminals attached to conductors are held by theresilient engagement of the bent extremities 40 and 52 but conductorswith the bent ends 88 and .89 are held much more firmly in position.

In order to provide terminals which are tightly lodged in place and alsomake improved contact engagement, terminals 99 and 81 as shown in Figs.3 and 4, the contact portions of which are formed with curves 87 orangular waves 92 and 94 adapted to seat the bent extremities 40 and 52of the spring contacts 24 and 44 between the waves of each terminal,making firm electrical connection with the spring contacts.

In all forms of terminals 89, 8d and 92 as shown by Figs. 2, 3 and 4,the inserted extremities of these terminals engage the connected crosspiece 56 and prevent or limit the insertion of the terminal contactsbeyond the cross piece, the engagernentof the bent extremities preventwithdrawal of the terminals.

At the end of the plug opposite the contact 16, it is formed withopposite inwardly rounded grooved portions 9'6 and with oppositeflattened sides 93 at rig-ht angles thereto so thatthe plug may-betightly gripped and-insertedin close quarters and forming: forefingerand thumb engaging portions. The flattened portion of the handle ismarked with plus) indicating the polarity of the contact tipconnection,and -(minus) indicatingthe polarity of the offset projection portion 46.The plug 16 when inserted in-a socket 100 will alwayscause engagernentof the plug with a central contact 102 in the end of the socket and theoffset portion 36 will always engage a wall portion 104--in the outerportion of a socket or receptacle. In making this engagement, it is notnecessary to ,turn. the plug into. the socket, but spring contact 44 towhich the offset,46 is connected has sufi'icient resilience so that itwill beheld firmly but removably in the shell and the contacttip'resilient-ly engaged with the Gentral contact 102. In removing theplug, it is pulled straight out, the olfset portion 46 yielding orspringing inwardly as the plug is removed.

Some automobiles are now equipped with 12 volt batteries and some stillhave 6 volt batteries. The lighter receptacle socket 1% for a standard12 volt battery is smaller (by .028 of an inch) than a standard 6 voltsocket, and a 6 volt accessoryplug is provided with a round protrusion101 which. projects, approximately .025 ofwaninch outwardly from theplug, at the forward end of its thickest midsection'portion; Nearthehandle end is a circle RPS-with the designation 61 therein, The 12 voltplug is similarly marked 12v in the circle 103, and the universalplugwithno protrusionhas no marking.

In producing the contact terminals for the conductors, they may bestamped from a continuous strip 106 of material having ears 108 andformed with locating or positioning openings 110 at-spaced distancesapart. The tongues84 are punched out of the material between theea-rsv1'08 and they may be offset oppositely at the same timeif desiredto form the opposite portions 82 which are bent about the-conductors.ably formed between the side portions 82 and the fiat portion 86 and thebent extremity 88 is preferably formed when the last terminal is cutfrom the strip. The tenninal forming operation is thus continuous and isusually performed on an automatic machine, preparing the terminals forseparate application to the ends of insulated conductors .as shown. Theterminals 31 having the teeth 83 and are similarly produced.

Accessory plugs of this kind are thus prepared completely without anysoldered connections; a firm electrical connection is made betweenconductors which are attached thereto; the terminals may be used fortrouble lights, portable spotlights, bottle warmers, battery chargers,defrosters, electric fans and many other electrical automobileaccessories. The plugs may also be used with other outlet sockets formaking similar electrical connections for other electrical accessories.The terminals may be furnished separately in connection with conductorshaving connected terminals as shown, and they may also be furnished withterminals which are. applied to other conductors connected to thedesired accessories.

While a preferred construction has been described in some detail, itshould be regarded byway of illustration and examples rather than as arestriction or limitation thereof, as many changes in the construction,combination and arrangement of the parts maybe made Without departingfrom the spirit and scope of the invention.

I' claim: Anelectrical accessory plug 'for a socket having an inner endcontact and a shell insulated therefrom, comprisinga longitudinallysplit hollow insulating casing, a pair of spring strip contacts-mountedin the casing having bent portions and adapted to flex therein, means inthe casing engaging one end of each contact to, holdthem firmly and inspaced relation, one contact having a slidable, tip at the other end ofthe contact projecting from the end of the-casing to resiliently engagethe inner end contact of a socket, the other strip contact having-anangular offset near its other end projecting laterally from anddepressible in the casing tomake 'a resilient connection with. the shellof the socket, means to contact the said engaged ends of the contacts inthe casing and extending therefrom to provide electric circuitconnections, said slidable tip having a flange at a distance from theend and inside of the casing, and the casinghaving a perforated crosspartition through which the tip extends and the flange engages the innersideof theipar-tition to limit the outward sliding movement of thetippressed outwardly by the bent portion of the resilient strip Contact,the hollow interior portion of the casing providing a space to receivethe bent portion transversely thereof, the interior of the casing havlnga fiat Notches 112 are prefers 5 portion adjacent the angular offset ofsaid strip for spacing the strip contacts apart and inward projectionsat the ends of the flat casing portion forming an inwardly openingrecess to receive the extremity of said bent portion to guide and limitthe movements of said strip contact and the tip as it is moved back andforth.

References Cited in the file of this patent UNITED STATES PATENTS1,949,141 Blaylock Feb. 27, 1934 2,238,696 Hanley Apr. 15, 19412,245,986 Krauss June 17, 1941 David July 10, 1945 Bellek Feb. 28, 1950Stanley Aug. 7, 1951 Knapp et a1. Mar. 24, 1953 Berg Aug. 4, 1953 Feltset al. Sept. 8, 1953 Ziemianin Oct. 27, 1953 Hurlbut Apr. 6, 1954 Birdet a1 Apr. 17, 1956 Morschel Feb. 8, 1957 FOREIGN PATENTS France May 3,1943

